Pison xenognathos Pulawski, 2018

Pulawski, Wojciech J., 2018, A Revision of the Wasp Genus Pison Jurine, 1808 of Australia and New Zealand, New Guinea, and the Pacific Islands (Hymenoptera: Crabronidae), Proceedings of the California Academy of Sciences 65, pp. 1-584 : 504-507

Pison xenognathos Pulawski , species nova

Figures 1215-1225.

NAME DERIVATION.– Xenognathos is derived from two Greek words: ξενος, strange, and γναθΟς, a jaw, mandible, a noun in apposition to the generic name; with reference to the unusual structure of this species mandible.

RECOGNITION. – Pison xenognathos is an all black species with three submarginal cells and erect setae on tergum I. It is unique among the Australian Pison in having the posterior mandibular margin with a rounded expansion (Figs. 1217, 1218). In addition, the inner mandibular margin is tridentate in the female (Fig. 1215) and bidentate in the male (Fig. 1216). Also, the propleuron has punctures that average several diameters apart and are visibly larger than those on the forecoxal venter. The broadly arcuate male clypeal lamella is also unusual (Fig. 1216). P. xenognathos is the only species in which the female combines the erect setae on tergum I with the presence of a psammophore on the gena, mandible, and the forefemur, and with the lower gena impunctate and asetose adjacent to the oral fossa.

DESCRIPTION.– Frons dull, punctures superficial, less than one diameter apart. Occipital carina joining hypostomal carina. Mandible with rounded expansion at posterior mandibular margin (Fig. 1217, 1218). Gena narrow in dorsal view. Labrum not emarginate. Anteromedian pronotal pit transversely elongate, about three times as long as midocellar diameter. Propleural punctures averaging several diameters apart, markedly larger than those on forecoxal venter. Scutum not foveate along flange, with short, evanescent longitudinal ridges adjacent to posterior margin; scutal punctures well defined, averaging less than one diameter apart; interspaces aciculate. Tegula slightly enlarged. Mesopleural punctures well defined, less than one diameter apart; interspaces microsculptured. Postspiracular carina present, about twice as long as midocellar diameter. Metapleural sulcus costulate between dorsal and ventral metapleural pits. Propodeum with irregular longitudinal carina separating side from dorsum and posterior surface and extending from gastral socket area toward spiracle; dorsum conspicuously, obliquely, irregularly ridged (ridges anastomosed); side ridged, punctate between ridges (ridges evanescent in ventral half in most specimens); posterior surface ridged. Posteroventral forefemoral surface closely punctate. Punctures of tergum I well defined, averaging one or two diameters apart posteromesally (before apical depression). Punctures of sternum II many diameters apart, apical depression impunctate.

Setae silvery, erect on frons, thorax, propodeum, forecoxal venter, femoral venters, and tergum I, sinuous on lower gena (see below for details); completely concealing integument on clypeus in both sexes. Apical depressions of terga I-IV with silvery, setal fasciae.

Body all black except mandible ferruginous mesally and apical tarsomeres brown.

♀.– Upper interocular distance equal to 0.66-0.68 × lower interocular distance; ocellocular distance equal to 0.7-0.8 × hindocellar diameter, distance between hindocelli equal to 1.2 × hindocellar diameter; eye height equal to 0.86-0.90 × distance between eye notches. Free margin of clypeal lamella obtusely angulate (Fig. 1215). Dorsal length of flagellomere I 2.1-2.2 × apical width, of flagellomere IX 1.2-1.3 × apical width. Lower gena (Fig. 1219), mandibular posterior

GEOGRAPHIC DISTRIBUTION (Fig. 1225).– Northern Territory, Queensland, Western Australia.

RECORDS.– HOLOTYPE: ♀, AUSTRALIA: Western Australia: Mount Augustus National Park at 24°18.0ʹS 116°47.6ʹE, 25 Apr – 7 May 2003, M.E Irwin and F.D. Parker ( ANIC).

PARATYPES: AUSTRALIA: Northern Territory: 65 km S Kalkarindji at 17°55.9ʹS 130°49.7ʹE, 11-17 June 2001, M.E. Irwin, F.D. Parker, and C. Lambkin (1 ♂, CAS) ; Gregory National Park at 16°12ʹ47ʺS 130°25ʹ11ʺE, 18 June 2001, M.E. Irwin, F.D. Parker, and C. Lambkin (1 ♂, CAS) ; Keep River National Park at 15°45ʹ44ʺS 129°05ʹ55ʺE, 10-20 June 2001, M.E Irwin and F.D. Parker (1 ♂, ANIC; 1 ♀, CAS) . Queensland: Isla Gorge National Park at 25°11ʹS 149°58ʹE, 13 Sept 1992, G. Daniels (1 ♀, QMB) . Western Australia: Cape Range National Park at 22°01.8ʹS 113°55.9ʹE, 28 Apr 2003, M.E Irwin and F.D. Parker (1 ♂, ANIC) ; Drysdale River at 15°02ʹS 126°55ʹE, 3-8 Aug 1975, I.F.B. Common and M.S. Upton (1 ♀, ANIC) ; 11 km E Marble Bar at 21°09.0ʹS 119°51.7ʹE, 2-14 May 2003, M.E Irwin and F.D. Parker (1 ♀, ANIC; 1 ♂, CAS) ; same data as holotype (1 ♀, CAS) .